The Enerlites 50121 WH 700W Slide Dimmer with Switch and LED optimizes system task lighting in residential and commercial environments. In addition to providing precise and dependable illumination settings, dimmers also help conserve energy wherever they are installed. Dimmers reduce energy consumption by cycling lighting on and off rapidly, thus increasing bulb life. Dimming your lights by a quarter increases your savings by approximately 20 percent. Dimming your lights by half increases your savings by approximately 40 percent! Lamp life is also extended up to 20 times when it is dimmed by half its rated wattage. The Switch on the Dimmer will allow you to turn the light on and off and leave slide at the dimming level you like. That way, you do not need to find the perfect level everytime. The LED is lit when the switch is off so you will be able to locate the switch in the dark.